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Biomedical subjects

G A Paletta

Publications and source records attributed to G A Paletta.

At least 19 recordsLinked to original sources
PubMed2000

Current concepts and controversies in meniscal imaging.

Analyzing meniscal abnormalities on MR images depends on a thorough understanding of the normal appearance of meniscal structures and on strict adherence to the MR imaging criteria for meniscal tears. When proper MR imaging technique is followed, meniscal tears can be diagnosed more acutely than with clinical examination alone, even in the presence of associated ligament injuries. The value of MR imaging lies in its ability to reveal details of meniscal tears, including location, morphology, length, depth, and possible stability. If this MR imaging information can be synthesized, it will dramatically affect treatment planning by helping to predict meniscal tears that are potentially reparable and tears that might not need surgical intervention.

Humans↗
PubMed2000

Limb salvage using distraction osteogenesis.

Distraction osteogenesis is a novel technique for the biological restoration of segmental bone defects. Definitive treatment of musculoskeletal tumors often requires large bony resections that can leave patients with significant osseous defects. Limb salvage using distraction osteogenesis is an attractive reconstructive alternative that may, in fact, offer advantages over other conventional techniques. We present our initial experience with the use of distraction osteogenesis in limb salvage.

Adolescent↗
PubMed2000

Surgical management of posterior shoulder instability in a ten-year-old boy: a case report and literature review.

Posterior shoulder instability is an uncommon clinical entity. It is even more rare in the pediatric population. We report the case of a 10-year-old boy who experienced recurrent posttraumatic posterior shoulder instability that eventually required surgical intervention. A review of the literature revealed no previous report of surgical management of nonobstetrical posttraumatic posterior glenohumeral instability in a skeletally immature individual.

Accidental Falls↗
PubMed1997

Posterolateral rotatory instability of the elbow: usefulness of MR imaging in diagnosis.

PURPOSE: To evaluate the efficacy of magnetic resonance (MR) imaging in the assessment of the normal and abnormal ulnar band of the lateral collateral ligament for diagnosis of posterolateral rotatory instability. MATERIALS AND METHODS: In nine symptomatic patients and nine asymptomatic subjects, MR imaging was performed with three-dimensional gradient-recalled and fast spin-echo sequences. The nine patients had clinical symptoms suggestive of subtle elbow instability. RESULTS: The components of the lateral collateral ligament were identified; tears of the ulnar band were noted in all symptomatic patients. The anterior fibers of the lateral collateral ligament, including the annular ligament, were intact. All symptomatic patients subsequently underwent surgical exploration and reconstruction. Positive clinical findings were demonstrated at examination performed while the patients were under anesthesia. All tears of the ulnar band were confirmed. CONCLUSION: With use of appropriate pulse sequences, MR imaging is an effective tool in the preoperative, noninvasive diagnosis of posterolateral rotatory instability.

Adolescent↗
PubMed1996

Accuracy of fat-suppressed three-dimensional spoiled gradient-echo FLASH MR imaging in the detection of patellofemoral articular cartilage abnormalities.

PURPOSE: To determine the accuracy of T1-weighted fat-suppressed (FS) three-dimensional (3D) fast low-angle shot (FLASH) magnetic resonance (MR) imaging for the detection of articular cartilage abnormalities of the patellofemoral joint. MATERIALS AND METHODS: Forty-one patients with suspected internal derangement of the knee were examined with a T1-weighted FS 3D FLASH sequence and subsequently underwent arthroscopy. The patellofemoral articular cartilage was graded blindly on both the MR and arthroscopic images with a modification of the Noyes classification scheme. RESULTS: For the detection of abnormal articular cartilage of the patellofemoral joint with the FS 3D FLASH sequence, sensitivity was 81%, specificity was 97%, and accuracy was 97%. Of the lesions detected on MR images, 77% were graded identically on MR and arthroscopic images. For the remaining 23%, MR imaging and arthroscopic ratings were within one grade of each other. CONCLUSION: T1-weighted FS 3D FLASH imaging is accurate for the detection and grading of articular cartilage abnormalities of the patellofemoral joint.

Adolescent↗
PubMed1995

Total knee arthroplasty after a previous patellectomy.

We performed a retrospective, matched-control analysis of the results of total knee arthroplasty with cement in twenty-two patients who had had a previous patellectomy for either a fracture of the patella (sixteen patients) or severe patellofemoral osteoarthrosis or chondromalacia patellae (six patients). Nine of the patients were men and thirteen were women. The average age at the time of the total knee arthroplasty was sixty-nine years (range, fifty-nine to seventy-four years). The average time from the patellectomy to the total knee arthroplasty was eight years (range, two to fourteen years). The patients were divided into two groups according to the type of implant that had been used. Group A (nine patients) had had insertion of a posterior stabilized prosthesis (a posterior cruciate-sacrificing implant) and Group B (thirteen patients) had had insertion of a posterior cruciate-sparing implant. Two computer-generated matched groups of patients who had had a total knee arthroplasty with insertion of implants that were identical to those in the study groups but who had not had a previous patellectomy served as controls. Group C consisted of patients who had had insertion of the same type of implant as that used in Group A, and Group D consisted of patients who had had insertion of the same type of implant as that used in Group B. All patients were evaluated before the arthroplasty and five years postoperatively with use of the rating system of the Knee Society.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Injuries about the hip and pelvis in the young athlete.

Athletic injuries to the hip and pelvis in pediatric and adolescent athletes, although uncommon, may encompass a wide spectrum of entities. A familiarity with this spectrum and a high index of suspicion in the proper clinical setting will ensure timely diagnosis and help to facilitate implementation of a proper treatment plan thereby assuring safe return to play.

Adolescent↗
PubMed1994

Knee injuries and Alpine skiing. Treatment and rehabilitation.

Alpine skiing is an increasingly popular recreational sport worldwide. While the overall injury rate has declined and the pattern of injury changed over the years, the incidence of knee injuries has not changed substantially and accounts for 20 to 30% of all alpine skiing injuries. Medial collateral ligament (MCL) injuries are the most common in skiing, accounting for 15 to 20% of all skiing injuries and 60% of knee injuries in skiers. Tears are commonly isolated, but may occur in association with other ligamentous injuries. Associated meniscal pathology is rare. Isolated MCL injuries are treated nonoperatively with a programme of initial immobilisation, early range-of-motion, and isometric quadriceps strengthening exercises. When full range of motion is achieved, a programme of progressive resistance exercises, isokinetic and closed chain exercises, and functional rehabilitation is instituted. Good results with return to skiing can be expected in most cases. Isolated lateral collateral ligament (LCL) injuries are rare in skiers. There is usually associated cruciate or arcuate ligament complex. Careful physical examination is essential to rule out associated ligament injuries and more complex instability patterns. In the rare case of isolated LCL injury, a similar approach to isolated MCL injury should be instituted. Anterior cruciate ligament (ACL) injuries have become increasingly common in skiers. This may reflect a true increase in the incidence or an improved awareness and ability to diagnose ACL injury. Physical examination and arthrometric analysis are important in assessing the integrity of the ACL. Radiographic and magnetic resonance imaging (MRI) evaluation may be helpful in assessing associated meniscal pathology. Treatment of the ACL-deficient knee is usually surgical. However, prior to reconstruction, a programme aimed at reducing effusion and regaining a full, pain-free range of motion is recommended. Surgical reconstruction is usually with the central third of the patella tendon using a bone-tendon-bone autograft. Postoperative rehabilitation employs a functional staged approach, requiring vigilant supervision by the surgeon. Isolated posterior cruciate ligament (PCL) injury is rare in skiing, constituting less than 1% of all knee injuries in most series. Careful physical examination must be employed to rule out associated arcuate ligament complex injury and more complex patterns of instability. Most isolated PCL injuries are treated nonoperatively with a programme of initial immobilisation in extension, ice, protected weight-bearing, early range-of-motion exercises and progressive isometric strengthening.(ABSTRACT TRUNCATED AT 400 WORDS)

Anterior Cruciate Ligament Injuries↗
PubMed1992

Accessory head of the biceps brachii. Case report demonstrating clinical relevance.

Although anatomic variations in the origin of both the coracobrachialis or biceps brachii have been observed, there have been no previous reports of clinical relevance. In a 22-year-old man, recognition and mobilization of an accessory long head of the biceps brachii was necessary for adequate exposure of the shoulder joint dislocation through a deltopectoral incision.

Adult↗
PubMedDate not supplied

Shoulder kinematics with two-plane x-ray evaluation in patients with anterior instability or rotator cuff tearing.

The goals of this study were to define biplanar glenohumeral kinematics and glenohumeral-scapulothoracic motion relationships in normal patients with a two-plane radiograph series and then in patients with anterior shoulder instability or rotator cuff tear both before surgery and after surgical repair and postoperative rehabilitation. A two-plane radiographic series of x-ray films in the scapular and horizontal (axillary) planes was performed. With these films, measurements of the relationship between the centers of the humeral head and glenoid and measurements of the component contributions of glenohumeral and scapulothoracic motion to total arm abduction were made. Six normal adults underwent x-ray evaluation to establish normal control values. Kappa analysis was used to determine reliability of technique. Eighteen patients with confirmed anterior shoulder instability (group A) and 15 with confirmed rotator cuff tears (group B) were studied before surgery. Seven (39%) of 18 of the patients in group A and all 15 (100%) of the patients in group B demonstrated superior translation of the humeral head during scapular plane abduction. In the horizontal plane 14 (78%) of 18 patients in group A (instability) and none in group B (rotator cuff tear) demonstrated abnormal anterior translation of the humeral head on the glenoid. Both groups demonstrated altered glenohumeral-scapulothoracic motion relationships compared with the normal control group. Two years after surgery 12 patients from group A and 14 patients from group B were restudied. All of these patients had demonstrated abnormalities of humeral head translation before surgery. For group A 12 (100%) of 12 patients demonstrated normal glenohumeral kinematics in both planes after open anterior stabilization. For group B 12 (86%) of 14 patients demonstrated normal glenohumeral kinematics in both planes after open rotator cuff repair. In group A the altered glenohumeral-scapulothoracic motion relationships persisted, whereas in group B these relationships became normal.

Adolescent↗
PubMedDate not supplied

Meniscal repair in very young children.

This article reports the cases of what we believe to be the youngest patients with traumatic meniscal tears treated by repair. The 2 cases were treated with different meniscal repair techniques. A review of the literature regarding traumatic meniscal tears in children is provided.

Arthroscopy↗
PubMedDate not supplied

The relationship of the femoral origin of the anterior cruciate ligament and the distal femoral physeal plate in the skeletally immature knee. An anatomic study.

We defined the anatomic relationship of the anterior cruciate ligament femoral origin to the distal femoral physis in the skeletally immature knee with use of 12 fresh-frozen human fetal specimens (ages, 20 to 36 weeks). Each specimen underwent magnetic resonance imaging, was dissected free of soft tissue, sectioned in the sagittal plane, and stained. The spatial relationship of 1) the epiphyseal side of the physeal proliferative zone to the nearest point of bony attachment of the anterior cruciate ligament and 2) the origin of the anterior cruciate ligament to the over-the-top position were measured. The same measurements were made in 13 skeletally immature knees (ages, 5 to 15 years). We found that the femoral origin of the fetal anterior cruciate ligament developed as a confluence of ligament fibers with periosteum at 20 weeks, vascular invasion into the epiphysis at 24 weeks, and establishment of a secure epiphyseal attachment by 36 weeks. In the fetus, the distance from the anterior cruciate ligament femoral origin to the epiphysis was 2.66+/-0.18 mm (range, 2.34 to 2.94). There was no significant change in this distance in adolescent specimens (2.92+/-0.68 mm; range, 2.24 to 3.62). The over-the-top position was at the level of the distal femoral physis.

Adolescent↗
PubMedDate not supplied

Patterns of meniscal injury associated with acute anterior cruciate ligament injury in skiers.

To determine if the incidence and patterns of meniscal injury associated with acute anterior cruciate ligament injury in skiers are different from those seen in individuals injured in nonskiing athletic activities, we reviewed the records of 150 patients with acute anterior cruciate ligament injuries. All patients had undergone arthroscopic evaluation within 21 days from the time of injury. There were 75 individuals who were injured while skiing and 75 individuals who sustained an injury in some other high-load athletic activity. Associated meniscal injury was documented at the time of arthroscopy and characterized by location, region, zone, depth, shape, size, and stability. Thirty-one of 75 skiers had an associated meniscal injury as compared to 47 of 75 of the nonskiers. This suggested a strong trend of decreased incidence of meniscal injury in the skier group, but the nonskiers had a higher incidence of major meniscal tears that required repair or partial meniscectomy. The location of the meniscal tear was also significantly different. The incidence of isolated lateral meniscal injury in skiers was higher than in nonskiers. There was a strong trend of increased incidence of medial meniscal involvement in the nonskiers than in the skiers. While there was no difference in the zone or region of tear between the two groups, the skier group was more likely to have a longitudinal tear of the posterior horn of the lateral meniscus. In both groups, lateral meniscal tears were more likely to require conservative treatment or partial meniscectomy while medial meniscal tears were more likely to be repaired than excised.

Adolescent↗
PubMedDate not supplied

The repair of osteochondral defects using an exogenous fibrin clot. An experimental study in dogs.

To evaluate the ability of an exogenous fibrin clot to hasten or optimize the repair of full-thickness articular cartilage defects, 4-mm diameter, full-thickness articular cartilage defects in 20 adult mongrel dogs were packed with an exogenous fibrin clot that had been prepared from each animal. The defects were created in a loaded and unloaded portion of the femoral trochlea. The healing response was then examined using routine histology at various intervals from 2 weeks to 6 months. Both the experimental (clot-filled) and control (empty) defects healed through a proliferation of fibrous connective tissue that eventually modulated into fibrocartilage. However, in the 2-, 4-, and 8-week animals, the experimental defects (both loaded and unloaded) demonstrated a more organized and advanced healing response than did the control defects. This difference was less pronounced in the 12- and 24-week animals. In all specimens, the clot-filled defects healed more uniformly than controls with less surface depression. In general, the unloaded sites were more uniform in healing than the corresponding loaded sites.

Animals↗
PubMedDate not supplied

The effect of allograft meniscal replacement on intraarticular contact area and pressures in the human knee. A biomechanical study.

To define the biomechanical effects of total lateral meniscectomy and of subsequent lateral meniscal allograft replacement on load transmission and distribution across the human knee, we mounted 10 fresh-frozen young human cadaveric knees on a mechanical testing system. Peak pressure and contact area profiles were determined at 0 degrees, 30 degrees, and 60 degrees of knee flexion using pressure-sensitive film and a densitometer. Load transmission profiles were determined for each knee in a sequential test order: 1) intact knee, 2) after lateral meniscectomy, 3) after implantation of size-matched meniscal allograft fixed with bone plugs, and 4) after release of the anterior and posterior horn attachments of the allograft. Total lateral meniscectomy resulted in a 45% to 50% decrease in total contact area. Allograft replacement increased total contact area by 42% to 65% as compared with total meniscectomy at all flexion angles. After release of the anterior and posterior horn attachments, contact area was identical to that after total meniscectomy. Total lateral meniscectomy resulted in a 235% to 335% increase in peak local contact pressure. Allograft replacement decreased these pressures by 55% to 65% at all flexion angles, but they remained significantly greater than those in the intact state. After release of the anterior and posterior horn attachments, contact pressures were identical to those after total meniscectomy. Compared with total meniscectomy, meniscal allograft transplantation significantly increases contact area and decreases peak local contact pressures, but any biomechanical advantages are lost without bone plug fixation of the anterior and posterior horns.

Adult↗